Allow clearing cookies for FlutterWebView

packages/webview_flutter/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.3.2
+
+* Added CookieManager to interface with WebView cookies. Currently has the ability to clear cookies.
+
 ## 0.3.1
 
 * Added JavaScript channels to facilitate message passing from JavaScript code running inside

packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterCookieManager.java

@@ -0,0 +1,54 @@
+package io.flutter.plugins.webviewflutter;
+
+import android.os.Build;
+import android.os.Build.VERSION_CODES;
+import android.webkit.CookieManager;
+import android.webkit.ValueCallback;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.MethodChannel;
+import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
+import io.flutter.plugin.common.MethodChannel.Result;
+
+class FlutterCookieManager implements MethodCallHandler {
+
+  private FlutterCookieManager() {
+    // Do not instantiate.
+    // This class should only be used in context of a BinaryMessenger.
+    // Use FlutterCookieManager#registerWith instead.
+  }
+
+  static void registerWith(BinaryMessenger messenger) {
+    MethodChannel methodChannel = new MethodChannel(messenger, "plugins.flutter.io/cookie_manager");
+    FlutterCookieManager cookieManager = new FlutterCookieManager();
+    methodChannel.setMethodCallHandler(cookieManager);
+  }
+
+  @Override
+  public void onMethodCall(MethodCall methodCall, Result result) {
+    switch (methodCall.method) {
+      case "clearCookies":
+        clearCookies(result);
+        break;
+      default:
+        result.notImplemented();
+    }
+  }
+
+  private static void clearCookies(final Result result) {
+    CookieManager cookieManager = CookieManager.getInstance();
+    final boolean hasCookies = cookieManager.hasCookies();
+    if (Build.VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
+      cookieManager.removeAllCookies(
+          new ValueCallback<Boolean>() {
+            @Override
+            public void onReceiveValue(Boolean value) {
+              result.success(hasCookies);
+            }
+          });
+    } else {
+      cookieManager.removeAllCookie();
+      result.success(hasCookies);
+    }
+  }
+}

packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/WebViewFlutterPlugin.java

@@ -4,11 +4,13 @@
 
 /** WebViewFlutterPlugin */
 public class WebViewFlutterPlugin {
+
   /** Plugin registration. */
   public static void registerWith(Registrar registrar) {
     registrar
         .platformViewRegistry()
         .registerViewFactory(
             "plugins.flutter.io/webview", new WebViewFactory(registrar.messenger()));
+    FlutterCookieManager.registerWith(registrar.messenger());
   }
 }

packages/webview_flutter/example/lib/main.dart

@@ -75,11 +75,14 @@ class WebViewExample extends StatelessWidget {
 enum MenuOptions {
   showUserAgent,
   toast,
+  clearCookies,
 }
 
 class SampleMenu extends StatelessWidget {
   SampleMenu(this.controller);
+
   final Future<WebViewController> controller;
+  final CookieManager cookieManager = CookieManager();
 
   @override
   Widget build(BuildContext context) {
@@ -100,6 +103,9 @@ class SampleMenu extends StatelessWidget {
                   ),
                 );
                 break;
+              case MenuOptions.clearCookies:
+                _onClearCookies(controller.data, context);
+                break;
             }
           },
           itemBuilder: (BuildContext context) => <PopupMenuItem<MenuOptions>>[
@@ -112,6 +118,10 @@ class SampleMenu extends StatelessWidget {
                   value: MenuOptions.toast,
                   child: Text('Make a toast'),
                 ),
+                const PopupMenuItem<MenuOptions>(
+                  value: MenuOptions.clearCookies,
+                  child: Text('Clear cookies'),
+                ),
               ],
         );
       },
@@ -125,6 +135,42 @@ class SampleMenu extends StatelessWidget {
     controller.evaluateJavascript(
         'Toaster.postMessage("User Agent: " + navigator.userAgent);');
   }
+
+  void _onClearCookies(
+      WebViewController controller, BuildContext context) async {
+    final String cookies =
+        await controller.evaluateJavascript('document.cookie');
+    final bool hadCookies = await cookieManager.clearCookies();
+    String message = 'There were cookies. Now, they are gone!';
+    if (!hadCookies) {
+      message = 'There are no cookies.';
+    }
+    Scaffold.of(context).showSnackBar(SnackBar(
+      content: Column(
+        mainAxisAlignment: MainAxisAlignment.end,
+        mainAxisSize: MainAxisSize.min,
+        children: <Widget>[
+          Text(message),
+          const Text('Cookies:'),
+          _getCookieList(cookies),
+        ],
+      ),
+    ));
+  }
+
+  Widget _getCookieList(String cookies) {
+    if (cookies == null || cookies == '""') {
+      return Container();
+    }
+    final List<String> cookieList = cookies.split(';');
+    final Iterable<Text> cookieWidgets =
+        cookieList.map((String cookie) => Text(cookie));
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.end,
+      mainAxisSize: MainAxisSize.min,
+      children: cookieWidgets.toList(),
+    );
+  }
 }
 
 class NavigationControls extends StatelessWidget {

packages/webview_flutter/ios/Classes/FLTCookieManager.h

@@ -0,0 +1,10 @@
+#import <Flutter/Flutter.h>
+#import <WebKit/WebKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FLTCookieManager : NSObject <FlutterPlugin>
+
+@end
+
+NS_ASSUME_NONNULL_END

packages/webview_flutter/ios/Classes/FLTCookieManager.m

@@ -0,0 +1,50 @@
+#import "FLTCookieManager.h"
+
+@implementation FLTCookieManager {
+}
+
++ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
+  FLTCookieManager *instance = [[FLTCookieManager alloc] init];
+
+  FlutterMethodChannel *channel =
+      [FlutterMethodChannel methodChannelWithName:@"plugins.flutter.io/cookie_manager"
+                                  binaryMessenger:[registrar messenger]];
+  [registrar addMethodCallDelegate:instance channel:channel];
+}
+
+- (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
+  if ([[call method] isEqualToString:@"clearCookies"]) {
+    [self clearCookies:result];
+  } else {
+    result(FlutterMethodNotImplemented);
+  }
+}
+
+- (void)clearCookies:(FlutterResult)result {
+  NSOperatingSystemVersion ios9 = (NSOperatingSystemVersion){9, 0};
+  if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:ios9]) {
+    [self clearCookiesIos9AndLater:result];
+  } else {
+    // support for IOS-8 tracked in https://github.com/flutter/flutter/issues/27624.
+    NSLog(@"Clearing cookies is not supported for Flutter WebViews prior to iOS9.");
+  }
+}
+
+- (void)clearCookiesIos9AndLater:(FlutterResult)result {
+  NSSet *websiteDataTypes = [NSSet setWithArray:@[ WKWebsiteDataTypeCookies ]];
+  WKWebsiteDataStore *dataStore = [WKWebsiteDataStore defaultDataStore];
+
+  void (^deleteAndNotify)(NSArray<WKWebsiteDataRecord *> *) =
+      ^(NSArray<WKWebsiteDataRecord *> *cookies) {
+        BOOL hasCookies = cookies.count > 0;
+        [dataStore removeDataOfTypes:websiteDataTypes
+                      forDataRecords:cookies
+                   completionHandler:^{
+                     result(@(hasCookies));
+                   }];
+      };
+
+  [dataStore fetchDataRecordsOfTypes:websiteDataTypes completionHandler:deleteAndNotify];
+}
+
+@end

packages/webview_flutter/ios/Classes/WebViewFlutterPlugin.m

@@ -1,4 +1,5 @@
 #import "WebViewFlutterPlugin.h"
+#import "FLTCookieManager.h"
 #import "FlutterWebView.h"
 
 @implementation FLTWebViewFlutterPlugin
@@ -7,6 +8,7 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
   FLTWebViewFactory* webviewFactory =
       [[FLTWebViewFactory alloc] initWithMessenger:registrar.messenger];
   [registrar registerViewFactory:webviewFactory withId:@"plugins.flutter.io/webview"];
+  [FLTCookieManager registerWithRegistrar:registrar];
 }
 
 @end

packages/webview_flutter/lib/webview_flutter.dart

@@ -469,6 +469,32 @@ class WebViewController {
   }
 }
 
+/// Manages cookies pertaining to all [WebView]s.
+class CookieManager {
+  factory CookieManager() {
+    if (_instance == null) {
+      final MethodChannel methodChannel =
+          const MethodChannel('plugins.flutter.io/cookie_manager');
+      _instance = CookieManager.private(methodChannel);
+    }
+    return _instance;
+  }
+
+  CookieManager.private(this._channel);
+
+  static CookieManager _instance;
+  final MethodChannel _channel;
+
+  /// Clears all cookies.
+  ///
+  /// This is supported for >= IOS 9 and Android api level >= 16.
+  /// returns true if cookies were present before clearing, else false.
+  Future<bool> clearCookies() => _channel
+      // ignore: strong_mode_implicit_dynamic_method
+      .invokeMethod('clearCookies')
+      .then<bool>((dynamic result) => result);
+}
+
 // Throws an ArgumentError if `url` is not a valid URL string.
 void _validateUrlString(String url) {
   try {

packages/webview_flutter/pubspec.yaml

@@ -1,6 +1,6 @@
 name: webview_flutter
 description: A Flutter plugin that provides a WebView widget on Android and iOS.
-version: 0.3.1
+version: 0.3.2
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/webview_flutter
 

packages/webview_flutter/test/webview_flutter_test.dart

@@ -15,13 +15,18 @@ void main() {
   final _FakePlatformViewsController fakePlatformViewsController =
       _FakePlatformViewsController();
 
+  final _FakeCookieManager _fakeCookieManager = _FakeCookieManager();
+
   setUpAll(() {
     SystemChannels.platform_views.setMockMethodCallHandler(
         fakePlatformViewsController.fakePlatformViewsMethodHandler);
+    SystemChannels.platform
+        .setMockMethodCallHandler(_fakeCookieManager.onMethodCall);
   });
 
   setUp(() {
     fakePlatformViewsController.reset();
+    _fakeCookieManager.reset();
   });
 
   testWidgets('Create WebView', (WidgetTester tester) async {
@@ -356,6 +361,31 @@ void main() {
     );
   });
 
+  testWidgets('Cookies can be cleared once', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const WebView(
+        initialUrl: 'https://flutter.io',
+      ),
+    );
+    final CookieManager cookieManager = CookieManager();
+    final bool hasCookies = await cookieManager.clearCookies();
+    expect(hasCookies, true);
+  });
+
+  testWidgets('Second cookie clear does not have cookies',
+      (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const WebView(
+        initialUrl: 'https://flutter.io',
+      ),
+    );
+    final CookieManager cookieManager = CookieManager();
+    final bool hasCookies = await cookieManager.clearCookies();
+    expect(hasCookies, true);
+    final bool hasCookiesSecond = await cookieManager.clearCookies();
+    expect(hasCookiesSecond, false);
+  });
+
   testWidgets('Initial JavaScript channels', (WidgetTester tester) async {
     await tester.pumpWidget(
       WebView(
@@ -639,3 +669,35 @@ Map<dynamic, dynamic> _decodeParams(Uint8List paramsMessage) {
   );
   return const StandardMessageCodec().decodeMessage(messageBytes);
 }
+
+class _FakeCookieManager {
+  _FakeCookieManager() {
+    final MethodChannel channel = const MethodChannel(
+      'plugins.flutter.io/cookie_manager',
+      StandardMethodCodec(),
+    );
+    channel.setMockMethodCallHandler(onMethodCall);
+  }
+
+  bool hasCookies = true;
+
+  Future<bool> onMethodCall(MethodCall call) {
+    switch (call.method) {
+      case 'clearCookies':
+        bool hadCookies = false;
+        if (hasCookies) {
+          hadCookies = true;
+          hasCookies = false;
+        }
+        return Future<bool>.sync(() {
+          return hadCookies;
+        });
+        break;
+    }
+    return Future<bool>.sync(() {});
+  }
+
+  void reset() {
+    hasCookies = true;
+  }
+}